KEF Ci250RRb-THX 10" THX In-Ceiling Subwoofer
£1,099
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Sold asSingle
Warranty2 years
KEF Ci250RRb-THX 10" THX In-Ceiling Subwoofer
£1,099
£915.83 ex VAT
Order by 1pm Mon–Fri for same-day dispatch
Free tracked UK delivery · Next day £11.99
30-day returns · full manufacturer warranty
Grille included as standard
Amplifier required
The Ci250RRb-THX is a passive subwoofer. It is driven by KEF's KASA500 subwoofer amplifier, sold separately.
Need speaker cable?
Allow about 10m per speaker for a typical run back to the amplifier. Webro 16/2 LSZH (low smoke, zero halogen) is the right cable for runs in ceilings and walls.
The KEF Ci250RRb-THX is an in-ceiling subwoofer for home cinemas and music systems where a floor-standing sub isn't wanted. An extra-long-throw 10in driver with a 150oz magnet delivers deep, low-distortion bass down to 20Hz, and it matches the Ci250RRM-THX in size and finish.
Why we like it
- Extra-long-throw 250mm (10in) driver with a 150oz magnet
- Bass down to 20Hz (±6dB) with 109dB maximum SPL
- Same 300mm cut-out and look as the Ci250RRM-THX for a matching ceiling
- Part of KEF's Extreme Home Theatre range
Installation notes
The Ci250RRb-THX needs a 300mm round cut-out and 147mm mounting depth from the surface. KEF recommends an ideal rear volume of 140 litres (70 litres minimum). It is a passive subwoofer driven by KEF's DSP-equipped KASA500 amplifier, which is sold separately.
Specifications
| Frequency Response | 20Hz - KASA setting (±6dB), open-backed |
| Drive Units | LF: 250mm (10in) |
| Maximum SPL | 109dB |
| Amplifier | KEF KASA500 (sold separately) |
| External Dimensions | Diameter 346mm; Depth 153mm |
| Cut-out Diameter | 300mm |
| Mounting Depth from Surface | 147mm |
| Net Weight | 5.6kg |
Questions we get asked
Does it come with a grille?
Yes. Every ceiling and in-wall speaker we sell comes with its grille in the box. Manufacturer photos often show the speaker with the grille removed so you can see the drivers, but the grille is always included.
Will it fit my ceiling?
You'll need a 300mm cut-out and at least 147mm of depth behind the ceiling surface. The visible trim is 346mm across. Standard plasterboard ceilings with joists are usually fine; check for pipes, cables and insulation before cutting. Not sure? Send us a photo or plan and we'll check it for you.
Do I need a fire hood?
If there's a habitable room above (for example a bedroom), or the ceiling forms part of a fire escape route, Building Regulations require each speaker to be fire-rated, usually with a fire hood fitted over the back. Hoods also cut sound travelling to the room above. See all fire hoods.
Is it sold singly or as a pair?
Priced per speaker. Add the quantity you need; most rooms use a pair.
When will it arrive?
Orders placed by 1pm Monday to Friday are dispatched the same day. Standard tracked delivery is £7.99, or free on orders over £50; next working day delivery is £11.99. Delivery details.
Can I return it?
Yes. Unused items can be returned within 30 days of delivery, and every product carries the full manufacturer warranty. Returns & warranty.